package com.resto.scm.web.util;

import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Created by KONATA on 2016/9/28.
 */
public class EmojiFilter {

	static Logger log = LoggerFactory.getLogger(EmojiFilter.class);

	/**
	 * 检测是否有emoji字符
	 * 
	 * @param source
	 * @return 一旦含有就抛出
	 */
	public static boolean containsEmoji(String source) {
		if (StringUtils.isBlank(source)) {
			return false;
		}

		int len = source.length();

		for (int i = 0; i < len; i++) {
			char codePoint = source.charAt(i);

			if (isEmojiCharacter(codePoint)) {
				// do nothing，判断到了这里表明，确认有表情字符
				return true;
			}
		}

		return false;
	}

	private static boolean isEmojiCharacter(char codePoint) {
		return (codePoint == 0x0) || (codePoint == 0x9) || (codePoint == 0xA) || (codePoint == 0xD)
				|| ((codePoint >= 0x20) && (codePoint <= 0xD7FF)) || ((codePoint >= 0xE000) && (codePoint <= 0xFFFD))
				|| ((codePoint >= 0x10000) && (codePoint <= 0x10FFFF));
	}

	/**
	 * 过滤emoji 或者 其他非文字类型的字符
	 * 
	 * @param source
	 * @return
	 */
	public static String filterEmoji(String source) {
		String str = source;
		try {
			if (!containsEmoji(source)) {
				return source;// 如果不包含，直接返回
			}
			// 到这里铁定包含
			StringBuilder buf = null;
			int len = source.length();
			for (int i = 0; i < len; i++) {
				char codePoint = source.charAt(i);
				if (isEmojiCharacter(codePoint)) {
					if (buf == null) {
						buf = new StringBuilder(source.length());
					}
					buf.append(codePoint);
				} else {
				}
			}
			if (buf == null) {
				str = source;// 如果没有找到 emoji表情，则返回源字符串
			} else {
				if (buf.length() == len) {// 这里的意义在于尽可能少的toString，因为会重新生成字符串
					buf = null;
					str = source;
				} else {
					str = buf.toString();
				}
			}
		} catch (Exception e) {
			str = "---";
			log.error("过滤emoji字符失败");

		}
		return str;
	}
}
